1. Field of the Invention
The present invention relates to a disc brake for a vehicle. More particularly, the present invention relates to a disc brake for a vehicle, which presses a friction pad against a disc through a wedge action.
2. Description of the Related Art
A disc brake is a device for obtaining braking force by pressing a friction pad against an outer surface of a disc rotating together with a wheel. The disc brake includes an electronic wedge brake (EWB) that presses a friction pad against a disc by using a sliding type wedge member. For instance, the wedge member presses the friction pad against the disc while being moved along an oblique side thereof by a driving device.
The EWB includes a driving motor for driving the wedge member, a screw shaft coupled with a rotating shaft of the driving motor, and a pressing member coupled to the screw shaft such that the pressing member can move back and forth according to the operation of the driving motor to press the wedge member against the disc.
According to the EWB, as the driving motor operates, the pressing member presses the wedge member against the disc, so that the friction pad makes contact with the disc. At the same time, the wedge member further presses the friction pad against the disc while being moved along an oblique side thereof, so that the braking action is achieved.
However, according to the disc brake for the vehicle of the related art, a first friction member, which is provided at one side of the disc brake where the driving motor is installed, makes contact with the disc according to the operation of the wedge member while moving toward the disc along the oblique side of the wedge member. In contrast, a second friction member, which is provided at the other side of the disc brake, linearly moves perpendicularly to the disc, so that the first and second friction members may not be aligned in the same position at the braking time. As a result, the moment is applied to the disc, so that uneven wear may occur in the friction members or the disc. In extreme case, the disc may be deformed.